This invention relates to a gauge for measuring and marking desired distances on such things as French mats.
French mats, called "washline mounts" in England, are classic fine-art mats, which originated in Europe. To make a fine French mat requires time, care, and practiced skill. An opening must be cut into at least one mat, and sometimes two, or three, and then ruled ink lines are generally drawn at desired intervals. These intervals may vary from mat to mat or from a particular form of mat to another particular form of mat. The mats may be, of course, of various sizes, but even when they are on the same size, taste will often dictate different spacings between the ruled ink lines. The areas between the lines may be left unfilled or may be filled in with watercolor or with other coloring material, such as a product I have devised, which is set forth in another patent application.
One of the principal problems in making a good French mat is to obtain rapidly the required accuracy in the spacing of the lines, and an important stage in the spacing is to mark the vertices of these lines on the mat adjacent each of the four corners of the cutout rectangle.
One cannot use the usual T-square without having to make two marks at each corner, and it is difficult to make these two marks sufficiently accurate so that the lines will meet at the precise, exact corner, with the spacing even on both sides. The distance of the cutout portion is exactly the same along each side margin and is usually the same for the top margin, but that is not true for the bottom margin. One can mark lines on the top portion by placing a ruler or other guide having a straight edge which bisects the mat corner and also the vertex of the adjacent cutout portion--in other words, along a line which joins the interior right angle of the cutout to the right angle of the mat itself. This, of course, will be accurate only if the cutout is so located that the distance between the cutout and the edge of the mat itself provides the same margin on both sides. It is not, therefore, usable on the bottom of the mat or even on the top of the mat unless that condition is met, as it generally is. Even then, prior art marking devices have tended to slip. The marking may be done with pencil or with a pen, or needle held in a proper holder or wrapped with tape on one end. Even when the mark is correctly made at the two top corners of the mat, there are still difficulties in making corresponding marks at the bottom.
Another problem is that when one uses a conventional scale on the diagonal, the spacing between the lines that lie parallel to the mat edges cannot be read on the scale. To obtain the actual distance from a cutout edge to a line to be ruled, one has to multiply the spacing on the diagonally held scale by the reciprocal of the square root of two. Thus, if one is marking along a diagonal, when the scale says one inch it will actually indicate a marginal spacing of 0.707 inch. It is difficult to accommodate these fractions.
Other similar problems exist in similar situations.
Thus, one object of the present invention is to enable one to make a French mat more rapidly and accurately than heretofore.
Another object of the invention is to enable one who is making a French mat to do so without having to calculate the diagonal distances as irrational multiples of the marginal distances, but to read the spacing directly and correctly on the diagonal scale in terms of the spacings between the parallel lines and edges.
Another object of the invention is to provide a gauge which can be accurately positioned and easily held in place while the marking is going on.
Another object of the invention is to provide a device in which a series of removable scales can be used. In this instance, the idea is to provide a whole series of styles or forms of mats in which, within each style or form, the lines surrounding the cutout are spaced at the same distances all around. These distances can be determined and applied to a particular pivoted scale which can easily be inserted into the assembly of this invention and become a part of it, but which is also removable when one goes to a different style or when one wishes to create a new style, or form.